Many customers in the machine building industry rely on contract manufacturers as an “extended workbench” by outsourcing sheet metal fabrication to laser job shops. On one hand, this provides suppliers with additional jobs. On the other hand, the constantly varying jobs and highly volatile scheduling also create logistical challenges for small and mid-sized companies as many laser job shops can no longer reliably plan ahead. These jobs can range from serial parts production to small component quantities. As a result, job shops are increasingly focusing on flexible processes. For suppliers, it is less a question of how quickly the individual machines work and more an issue of the most efficient way of linking the individual processing steps and reducing processing times. The leveling and deburring process steps help to ensure smoothly functioning procedures, short processing times and less rework.
Roller levelers ensure flat sheet metal parts that are largely free of internal stresses. However, many suppliers in the machine building industry still forego the use of their own leveling machine. Yet even when purchasing the materials, it has become clear that the acquisition of a leveler pays for itself for laser job shops. Companies with their own leveling equipment benefit from a broader range of purchasing options. They can purchase lower-cost sheets and level these themselves.
Unevenness and internal stresses in the sheets are often invisible to the naked eye. However, their impact becomes apparent in the following processing steps. During laser cutting, for example, internal stresses cause portions of the sheet to deform during processing. This can cause damage to the laser head and result in delays.
After cutting, the sheet metal parts are often bent and formed with a press brake. The value of leveling the material beforehand also becomes apparent during this process as it also prevents disruptions. Press brakes can work more precisely with leveled sheet metal parts. Leveling is especially important when robots feed the press brake which then processes the sheet metal automatically. Unlike employee-guided processes, the machine cannot inspect the panel and determine whether the panel is clamped into the equipment without any tension. Employees have to be able to rely on the parts being properly formed after the process.
The welding process reveals the true strength of levelers. Leveled parts can be quickly and precisely clamped into welding fixtures, drastically reducing welding preparation times. The welding process itself can also be carried out without any problems when leveled parts are used. Suppliers utilizing robot-controlled welding systems are even more reliant on leveled sheet metal parts because the robots require an accurate leveling gap to achieve consistent welding results.
Nowadays, customers require even more demanding flatness tolerances for their sheet-metal assemblies. Parts that have not been leveled may exceed these tolerances. If multiple un-leveled sheet metal parts are welded together, the resulting assembly may not comply with the tolerances. Therefore, there is a risk of extensive rework or customer complaints due to inadequate quality.
Burrs resulting from processes such as laser or plasma cutting can significantly impair the subsequent sheet metal processing. Aside from the risk of injury due to the sharp edges on the sheet metal parts after cutting, the burrs can also cause scratches when the parts are stacked in the warehouse. This results in quality losses.
Deburring machines such as the EdgeBreaker® series from ARKU remove the burrs and round the edges of sheet metal parts rapidly and reliably. The state-of-the-art deburring technology delivers high-quality sheet metal parts which benefit your downstream sheet metal processing. This not only reduces the wear and tear on the press brakes and leveling machines, cleanly deburred parts are easier to prepare for welding and also simplify the assembly process.
Coatings applied to sharp panel edges can flake off, allowing the surface below to corrode. Rounded edges are essential to improve paint adhesion. Oxide on the cut edges can impair the welding process, leading to improper welds.
As a whole, utilizing a deburring machine significantly improves the quality of your parts and increases the effectiveness of your processes.
Milling processes also benefit from leveled material. But not because leveling provides the parts with the precision of a milled surface. Instead, leveling greatly reduces the amount of milling work: if the part has been leveled, less material needs to be removed. The raw material itself can also be thinner, reducing your material costs. Moreover, leveled parts fit into the fixture of the milling machine better than uneven pieces and require less machining time.
The processes at sheet metal fabricators have large room for improvement. Laser speeds are constantly increasing. Automated operation from the warehouse to laser cutting has almost become a reality. Downstream processes need to keep pace in order to maintain competitive pricing and delivery schedules.
In view of this, laser job shops are increasingly relying on intelligently networking the individual processing steps in order to optimize the process chain within their company. ARKU offers a robot, for example, which autonomously carries out the handling processes for leveling and deburring machines. Using a camera system, the robot identifies the different parts and feeds them into the machine. The system is optimized with very short set-up times to handle the widely varying parts spectrum typical among contract manufacturers. At the ARKU’s open house in Baden-Baden from May 20th to 24th, 2019, ARKU presented and demonstrated an automated leveling process including flatness inspection and stacking of the finished parts.